Read more... • Another tornado rips through village - this time in Wales

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The warning, published on Torro's website, applies to parts of south-west England, East Wales, south Wales and much of southern, central and eastern England.

It said: "The highest tornado risk would appear to be along and close to the south coast."

On Saturday a tornado wreaked havoc in the village of Boarhunt in Hampshire.

It flattened sheds and greenhouses, brought down power lines and ripped the roof off a mobile home, causing thousands of pounds of damage.

Torro, which is based in Oxford, issues three levels of warning of severe weather, convective outlook; convective discussion; and severe thunderstorm and tornado watches.

It stopped short of issuing the highest level of alert - a convective outlook - because it deemed the likelihood of severe, widespread thunderstorms was "rather marginal".

Rachel Vince, forecaster at the MeteoGroup UK, said: "We have had reports of a tornado near Portsmouth on Saturday.

"The main concern is general wind and heavy rain through the next 24 to 48 hours."

More than 20 properties were affected by what is believed to have been a tornado in the early hours of this morning.

Emergency services were called to Bow Street in Aberystwyth, West Wales, shortly after 2am. A spokesman for Dyfed Powys Police said: "It was apparent that what is believed to be a tornado had struck parts of the village.

"Commercial and residential premises, vehicles and caravans were damaged."

He added that nobody was thought to have been injured.

Mid and West Wales Fire Service also attended and said the high winds had affected 23 properties in the area.

Crews were involved in making damaged roofs and chimneys safe until about 6am.

The main road through Bow Street, the A487, was closed while the properties were made safe and the highways authority cleared debris.

The railway track behind the properties was also closed due to fallen trees and debris on the line. The police spokesman added: "A further, more detailed assessment of the full extent of the damage caused will be achieved at first light.

"Police officers are remaining in the area overnight to provide high visibility policing and public reassurance."